248 PRACTICAL ORGANIC CHEMISTRY
the same result. According to Henry the reaction with HC1
takes place in several steps,
CHa.COOH + C,H,OH = CH3C(OH)2OC2Ha.
CH3.C(OH)oOC2II5 + HCl = CH3C(OH)C10C2H3 -I- H,O.
CH3.C(OH)ClOCoHn = CH3.COOC2H5 + HCl.
Other methods for the preparation of esters are by the action of
alcohol on the acicl chloride or anhydride (see Reactions, p. 75),
or by boiling' up the dry powdered silver salt of the acid with the
CHa.COOAg + C2H5I = CH3.COOCJIn + Agl.
The esters are, for the most part, colourless liquids or solids of
low m. p., with a fruity smell and insoluble in water. They are
hydrolysed by potash (most readily with alcoholic potash) and
give amides with ammonia,
.CH3.COOC3H5 + NH3 = CH3.CONH2 + C2H5OH.
Ethyl Acetoacetate. -The explanation of the manner in
which this substance is produced has been given in the account
of the preparation. The result was arrived at, not by the isola-
tion of the intermediate compound formed by the union of
ethyl acetate with sodium ethylate, but by analogy with the
behaviour of benzoic methyl ester with sodium benzylate, which
gave the same additive product as that obtained by combining'
benzoic benzyl ester with sodium methylate, showing that such
combinations could occur,
Also by the fact that sodium only attacks ethyl acetate in
presence of ethyl alcohol, although the quantity of the latter
may be very minute. Similar reactions have been effected
with either metallic sodium or sodium ethylate by Claisen,